Composition of epoxy resin and clathrate of tetrakisphenol and epoxy-reactive curing compound

ABSTRACT

The present invention has an object to provide curatives for epoxy resins and curing accelerators for epoxy resins, which both have improved subliming and decomposing properties and which, when mixed with an epoxy resin, enable the mixture to be greatly improved in thermal stability that is extremely important for the control of a curing reaction and to have a prolonged pot life (stability as a one-pack mixture comprising the epoxy resin, curative, etc.) and improved curability at low temperatures. 
     The curative is characterized by being a clathrate comprising a tetrakisphenol compound represented by a general formula [I];                    
     wherein X represents (CH 2 )n, wherein n is 0, 1, 2 or 3, and R 1  to R 8  each represents hydrogen, a lower alkyl, optionally-substituted phenyl, halogeno or a lower alkoxy, and the curing accelerator is characterized by being a clathrate comprising a tetrakisphenol compound represented by the general formula [I] shown above and a compound accelerating the curing of a compound which reacts with the epoxy group of an epoxy resin to cure the resin.

FIELD OF INVENTION

The present invention is related to epoxy resin compositions and to acurative for epoxy resins and a curing accelerator for epoxy resins,both of which contain a tetrakisphenol compound.

BACKGROUND ART

Epoxy resins are characterized as one having various excellentproperties, such as chemical proof, corrosion resistance, mechanicalproperty, thermal property, adhesive property to various materials,electric property, and easy handling property under any condition, andare widely used for adhesives, paints, electrometal materials andcomplex materials. An epoxy group in an epoxy resin is a functionalgroup which has great distortion therein and enormous reactivity, beingreactive to both acids and bases, and is capable of curing epoxy resinsby virtue of such high reactivity to make a resin into three dimensionstructure. An epoxy resin composition is composed of an epoxyprepolymer, which contains more than 2 epoxy groups in a molecule, and acurative, and is normally added with a curing accelerator, a denaturant,a filler, etc. depending upon the use thereof. It is known that theproperty of a cured-resin is subject to the type of a curative used, andvarious curatives have ever been used for industrial purposes. Epoxyresin compositions can be divided into two main types, the one isone-pack mixture and the other is two-pack mixture type, the former typecan be cured, for example, by heating, pressing or allowing thecomposition itself to stand. The other type, two-pack mixture type, canbe cured by admixing the main component and either a curative or acuring accelerator just before use and subsequently heating, pressing orallowing the mixture to stand, for example. Normally, the epoxy resincompositions are prepared into two-pack mixture-types, which are widelyused for parts to be used in the fields of electric appliances industry,automobile industry and aircrafts industry, since two-pack mixture typehas excellent properties in terms of the strength of cured-products,thermal property, electricity property, etc., though it is not easy tohandle and not economical from operation point of view. However, thetwo-pack mixture type has problems that, (1) since it has short potlife, that means time maintainable the state of prepared composition tobe usable for curing, operational performance is ceased due to startingof partial curing of the composition during the preparation, whichcauses the increase of viscosity of the composition, and (2) thephysicochemical property of the composition is ceased by incorrectmixing or incomplete preparation. Therefore, latent-type curatives andcuring accelerators, which are prepared as one-pack mixture type, havebeen desired. Latent-type curatives and curing accelerators are definedas ones, in which a curative and a curing accelerator compounded in aresin are stable at room temperature, and which may induce a curingreaction by virtue of an effect such as heating. For the initiation ofcuring reactions, heat, light, pressure, etc. may be effective, however,it is rather normal to use heating. For stabilizing the effect ofcuratives and curing accelerators, microcapsules thereof have been used,however, such microcapsules do not have sufficient mechanical strength,and therefore, there have been a problem in stability of thosemicrocapsules such that they cannot stand for a process of blending toadjust resin compositions.

It is known that there are several types of curatives, for example, (1)addition-type curatives, the molecules of a curative are alwaysincorporated into a cured-resin by virtue of the reaction with epoxygroups, (2) polymerization-type curatives, of which moleculesenzymatically induce opening of rings of epoxy groups without causingincorporation of molecules of the curative into resins to causepolymerization and addition reaction between oligomers, and (3)photoinitiation-type curatives, which initiate curing by gainingirradiation of ultraviolet rays. Irrespective of the type as describedabove, it is the most important thing to carry on polymerizationaddition reaction under a fixed condition and more homogeneously andfaster in order to obtain a cured-product in the stable state. However,we have still problems when using any of existing curatives such that(1) curing reaction by using any of existing curatives stops before thecompletion of the reaction due to increase of viscosity of resins, (2)there are many inhibitory factors against a curing reaction, (3) somesevere conditions are required for completing a curing reaction, and (4)a great amount of a curative is required for carrying out a curingreaction homogeneously, and therefore, curing accelerators which enableto proceed homogeneous and fast polymerization addition reaction under amild condition have badly been required. The curing accelerator isdefined here as the one which makes the curing time of a curative forcuring epoxy resins shorter and makes the curing reaction faster andmore smooth. For addition-type curatives, such as primary amines andsecondary amines, alcohols or phenols are used as a curing acceleratorfor promoting a polymerization-addition reaction. However, there is yeta problem in those use in general, since in case of using any ofpolymerization-type curatives, such as imidazoles, anion polymerizationto be developed between oligomers tends to be inhibited by such alcoholsand phenols.

In Japanese Patent Laid-open No. Hei 5-194711 Gazette, an epoxy resinwhich is compounded with a clathrate comprising both a curative forepoxy resins and a curing accelerator for epoxy resins with amultimolecular (phenol) host compound is described. Specifically, amethod for curing epoxy resins by adding a clathrate comprising2-ethyl-4-methylimidazole and2,2′-methylenebis(4-methyl-6-t-butylphenol) at a ratio of 1:1 is addedinto an epoxy resin at a rate of several % based on imidazole isdescribed in the Gazette.

However, although there is a description that a pot life (stability as aone-pack mixture) of the compounded-epoxy resin described above can beprolonged sharply, it is just a comparison with a similar clathrate,cyclodextrin, and the performance of that compounded-epoxy resin is notyet satisfactory for the use in a practical scale. Also, there is nodescription on the thermal stability and the curability at lowtemperature in the Gazette.

In Japanese Patent Laid-open No. Hei 5-201902 Gazette, there is adescription of a clathrate comprising a tetrakisphenol compound and animidazole compound, although there is no definite description that theclathrate can be used as a curative and a curing accelerator for epoxyresins.

In Japanese Patent Laid-open Nos. Sho 60-40125 and Hei 8-151429Gazettes, an use of a salt of an imidazoline compound and a polyhydricphenol as a curative for epoxy resins is described. However, suchcurative is neither crystalline solid nor a clathrate and does not givesufficient stabilizing effect as a one-pack mixture, in practice. Again,in U.S. Pat. No. 3,519,576, an use of a salt of an amine compound and apolyhydric phenol compound as a curative for epoxy resins is described.However, this salt is not practically satisfactory as a curative in thelight of the stability as a one-pack mixture. In U.S. Pat. No.4,845,234, an use of a salt of an imidazole compound and a polyhydricphenol compound as a curative for epoxy resins is described. However,the state of this salt is highly-viscous liquid and is not a clathratecompound, and it is not the one which can be practically used withsatisfaction in the light of the stability as a one-pack mixture.

In Japanese Patent Publication No. Hei 6-9868, a disclosure of the useof a salt of a tetrakisphenol compound and an imidazole compound as acurative for epoxy resins is made, however, there is no definitedescription about the use. In this publication, a salt of an imidazolecompound and a polyhydric phenol compound is disclosed, however, thestate of the salt is highly-viscous liquid and is not formed as aclathrate compound. Though there is a description as to the stability asa one-pack mixture, etc., such effect seems to be practicallyunsatisfactory. Furthermore, the description lacks an explanation on theheat stability and the curability at low temperatures.

In Japanese Patent Publication No. 2501154 and Japanese PatentPublication No. Hei 7-74280, there is a description that atetrakisphenol skeleton be introduced into a produced-resin by using atetrakisphenol compound as a curative. In this case, there is acharacteristic in the resin that a tetrakisphenol skeleton be introducedinto the produced-resin, where the tetrakisphenol compound as a curativeis used at a greater rate of 0.5-2 moles against 1 mole of epoxy groups.As the effect, only description on the stability as a one-pack mixtureis given, whereas no description is given about the stability on heatand the curability at low temperatures.

Considering such background as described above, it is an object of thepresent invention to provide a curative for epoxy resins and a curingaccelerator for epoxy resins, which have improved subliming property anddecomposing property, remarkably-improved thermal stability which isextremely important for the control of a curing reaction, a prolongedpot life (stability as a one-pack mixture comprising an epoxy resin anda curative) and improved curability at low temperatures. Furthermore,the present invention is also directed to provide an epoxy resincomposition which provides stable cured-products even under a mildcondition by proceeding a curing reaction of an epoxy resin faster andsmoothly, etc.

DISCLOSURE OF INVENTION

For solving the problem as described above, it is found that the thermalstability of a curative for epoxy resins and a curing accelerator forepoxy resins in an epoxy resin composition can be improved by includingeither the curative or the curing accelerator with a tetrakisphenol hostcompound, allowing the pot life of such curative and curing acceleratorremarkably longer, and further improving the curability thereof at lowtemperatures.

Further, it is found by the inventors that a fast and smooth curingreaction of epoxy resins can be accomplished by simultaneously using aspecific tetrakisphenol compound together with a compound which reactswith the epoxy group of an epoxy resin to cure the resin, and thatstable cured-products can be obtained even under a mild condition forthe reaction.

Therefore, the present invention is directed to a curative for epoxyresins, characterized that the curative is composed of a clathrate of atetrakisphenol compound represented by a general formula [I];

wherein X represents (CH₂)n, wherein n is 0, 1, 2 or 3, and R¹ to R⁸each represents hydrogen, a lower alkyl, optionally-substituted phenyl,halogeno or a lower alkoxy, and a compound which reacts with the epoxygroup of an epoxy resin to cure the resin, and to a curing accelerator,characterized by being a clathrate comprising a tetrakisphenol compoundrepresented by the general formula [I] shown above and a compoundaccelerating the curing of a compound which reacts with the epoxy groupof an epoxy resin to cure the resin.

The present invention is directed to an epoxy resin compositioncharacterized by containing at least one of a clathrate comprising atetrakisphenol compound represented by a general formula I and acompound which reacts with the epoxy group of an epoxy resin to cure theresin and a clathrate comprising a tetrakisphenol compound representedby the general formula I and a compound other than the tetrakisphenolcompound, which accelerates the curing of an epoxy resin, and preferablyto an epoxy resin composition wherein said clathrate is contained at acontent range of from 0.001 to 0.1 mole based on 1 mole of epoxy groups.

Furthermore, the present invention is also directed to an epoxy resincomposition characterized by containing a curative which reacts with theepoxy group of an epoxy resin to cure the resin and a tetrakisphenolcompound represented by a general formula [I];

wherein X represents (CH₂)n, wherein n is 0, 1, 2 or 3, and R¹ to R⁸each represents hydrogen, a lower alkyl, optionally-substituted phenol,halogeno or a lower alkoxy, in an amount of from 0.001 to 0.1 mole basedon 1 mole of epoxy groups.

As examples for the compound (curative) which reacts with the epoxygroup of an epoxy resin to cure the resin and the compound (curingaccelerator) accelerating the curing of the resin, amines imidazoles,amides, esters, alcohols, thiols, ethers, thioethers, phenols,phosphorus compounds, ureas, thioureas, acid anhydrides, Lewis acids,onium salts, active silica compounds-aluminium complexes, etc. aregiven, however, any ones can be optionally selected from the ones whichare customarily and conventionally-used as a curative or a curingaccelerator for epoxy resins without any constraints.

As amines, for examples, aliphatic amines, alicyclic and heterocyclicamines, aromatic amines, modified amines and the like can be used.

As examples for the aliphatic amines: ethylenediamine,trimethylenediamine, tetramethylenediamine, hexamethylenediamine,diethylenetriamine, triethylenetetramine, tetraethylenepentamine,dipropylenediamine, dimethylaminopropylamine, diethylaminopropylamine,trimethylhexamethylenediamine, pentanediamine,bis(2-dimethylaminoethyl)ether, pentamethyidiethylenetriamine,alkyl-t-monoamine, 1,4-diazabicyclo(2,2,2)octane(triethylenediamine),N,N,N′,N′-tetramethylhexamethylenediamine,N,N,N′,N′-tetramethylpropylenediamine,N,N,N′,N′-tetramethylethylenediamine, N,N-dimethylcyclohexylamine,dimethylaminoethoxyethoxy ethanol, dimethylaminohexanol and the like canbe given.

As examples for the alicyclic and heterocyclic amines; piperidine,piperidine, menthanediamine, isophoronediamine, methylmorpholine,ethylmorpholine, N,N′,N″-tris(dimethylaminopropyl)hexahydro-s-triazine,3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxyspiro(5,5)undecaneadacto,N-aminoethylpiperadine, trimethylaminoethylpiperadine,bis(4-aminocyclohexyl)methane, N,N′-dimethylpiperadine,1,8-diazabicyclo(4,5,0)undecene-7 and the like can be given.

As examples for the aromatic amines, o-phenylenediamine,m-phenylenediamine, p-phenylenediamine, diaminodiphenylmethane,diaminodiphenylsulfone, benzylmethylamine, dimethylbenzylamine,m-xylenediamine, pyridine, picoline and the like can be given.

As examples for the modified polyamines, polyamines added with epoxycompounds, polyamines added by Michael reaction, polyamines added byMannich reaction, polyamines added with thiourea, ketone-blockedpolyamines and the like can be given.

As examples for other amines, dicyandiamide, guanidine, organic acidhydrazid, diaminomaleonitrile, amineimide, trifluoroboron-piperidinecomplex, trifluoroboron-monoethylamine complex and the like can begiven.

As examples for the imidazole compounds, imidazole, 2-methylimidazole,2-ethylimidazole, 2-isopropylimidazole, 2-n-propylimidazole,2-undecyl-1H-imidazole, 2-heptadecyl-1H-imidazole,1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-1H-imidazole,4-methyl-2-phenyl-1H-imidazole, 2-phenyl-4-methylimidazole,1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole,1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-undecylimidazole,1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazoliumtrimellitate, 1-cyanoethyl-2-undecylimidazolium trimellitate,1-cyanoethyl-2-phenylimidazolium trimellitate,2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine,2,4-diamino-6-(2′-undecylimidazolyl)-ethyl-s-triazine,2,4-diamino-6-[2′-ethyl-4-imidazolyl-(1′)]-ethyl-s-triazine,2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine isocyanuricacid addition products, 2-phenylimidazole isocyanuric acid additionproducts, 2-methylimidazole isocyanuric acid addition products,2-phenyl-4,5-dihydroxymethylimidazole,1,2-phenyl-4-methyl-5-hydroxymethylimidazol,1-cyanoethyl-2-phenyl-4,5-di(2-cyanoethoxy)methylimidazole,1-dodecyl-2-methyl-3-benzylimidazolium chloride,1-benzyl-2-phenylimidazole hydrochloride, 1-benzyl-2-phenylimidazoliumtrimellitate and the like can be given.

As examples for the imidazoline compounds, 2-methylimidazoline,2-phenylimidazoline and the like can be given.

As examples for the amide compounds, polyamides obtainable by means ofpolymerization of dimaric acid and polyamine can be given, and asexamples for ester compounds, active carbonyl compounds, such as aryland thioaryl esters of carboxylic acids, can be given. Further, asexamples for phenol, alcohols, thiols, ethers and thioether compounds,phenol novolac, cresol novolac, polyol, polymercaptan, polysulfide,2-(dimethylaminomethylphenol), 2,4,6-tris(dimethylaminomethyl)phenol,tri-2-ethylhexyl hydrochloride of 2,4,6-tris(dimethylaminomethyl)phenoland the like can be given.

Further, as examples for urea, thiourea and Louis acid type curatives,butylated urea, butylated melamine, butylated thiourea, trifluoroboronand the like can be given.

As examples for phosphorus-containing curatives, organic phosphinecompounds, such as alkyl phosphines including ethyl phosphine and butylphosphine, primary phosphines, such as phenyl phosphine, dialkylphosphines, such as dimethyl phosphine and dipropyl phosphine, secondaryphosphines, such as diphenyl phosphine and methylethyl phosphine,tertial phosphines, such as trimethyl phosphine and triethyl phosphine,and the like can be given, whereas as examples for acid anhydride typecuratives, phthalic anhydride, hexahydrophthalic anhydride,methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride,endomethylenetetrahydrophthalic anhydride, methylendomethylenetetrahydrophthalic anhydride, maleic anhydride, tetramethylenemaleicanhydride, trimellitic anhydride, chlorendic anhydride, piromelliticanhydride, dodecenylsuccinic anhydride, benzophenonetetracarboxylicanhydride, ethylene glycol bis(anhydrotrimellitate), methylcyclohexenetetracarboxylic anhydride, polyazelaic anhydride and the like can begiven.

As examples for onium salt type and active silica compound-aluminiumcomplex type curatives, aryldiazonium salts, diaryliodonium salts,triarylsulfonium salts, triphenylsilanol-aluminium complex,triphenylmethoxysilane-aluminium complex, silylperoxide-aluminiumcomplex, triphenylsilanol-tris(salicylaldehydato)-aluminium complex andthe like can be given.

In the present invention, the tetrakisphenol compound forming aclathrate compound with the curative or the curing accelerator asdescribed above is a compound represented by a general formula [I];

wherein X represents (CH₂)n, wherein n is 0, 1, 2 or 3, and R¹ to R⁸ maybe the same or each independently different, and which represents, forexamples, hydroxy, a C₁-C₆ lower alkyl, such as methyl, propyl,isopropyl, n-butyl, isobutyl, t-butyl, n-hexyl and cyclohexyl, phenyloptionally-substituted with halogeno, a lower alkyl or the like,halogeno, such as fluorine, chlorine, bromine and iodine, or a C₁-C₆lower alkoxy, such as methoxy, ethoxy and t-butoxy.

Any tetrakisphenols represented by a general formula [I] can be used inthe present invention without any cobstraint, and the followings aregiven as the definite examples, those are1,1,2,2-tetrakis(4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-methyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-chloro-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-dichloro-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-bromo-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-dibromo-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-t-butyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-fluoro-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-difluoro-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-methoxy-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3,5-dimethoxy-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-chloro-5-methyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-bromo-5-methyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-methoxy-5-methyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-t-butyl-5-methyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-chloro-5-bromo-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis(3-chloro-5-phenyl-4-hydroxyphenyl)ethane,1,1,2,2-tetrakis[(4-hydroxy-3-phenyl)phenyl]ethane,1,1,3,3-tetrakis(4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-methyl-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-dimethyl-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-chloro-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-dichloro-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-bromo-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-dibromo-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-phenyl-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-diphenyl-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-methoxy-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-dimethoxy-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3-t-butyl-4-hydroxyphenyl)propane,1,1,3,3-tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)propane,1,1,4,4-tetrakis(4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3-methyl-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3,5-dimethyl-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3-chloro-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3,5-dichloro-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3-methoxy-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3,5-dimethoxy-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3-bromo-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3,5-dibromo-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3-t-butyl-4-hydroxyphenyl)butane,1,1,4,4-tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)butane and the like.These tetrakis phenol compounds can be used in either form of single ora combination of 2 or more thereof in the present invention.

The synthesis of a clathrate comprising a tetrakisphenol compound andeither a compound which reacts with the epoxy group of an epoxy resin tocure the resin (a curative) or a compound accelerating the curing of theresin (a curing accelerator) can be achieved at high selectivity and ahigh yield, by adding a tetrakisphenol compound into liquid amine orimidazole compound, which are either a curative or a curing accelerator,to allow them to a reaction in case such amine and imidazole are liquidcompounds, or by adding a tetrakisphenol compound into the suspension ofmuch amine or imidazole in case they are solid compound, or by allowinga tetrakisphenol powder to a solid-phase reaction directly with suchsolid amine or imidazole. The clathrate according to the presentinvention is produced basing on a mechanism that the molecules of aguest compound penetrate into the space in the crystalline latticeconstituted by the molecules of a host compound. Consequently, for aguest compound, easiness in such penetration might be determined by thesize, the configuration, the polarity, the solubility, etc. of themolecules of a guest compound. The state of the clathrate prepared inthe present invention is crystalline solid.

As examples for the uncured epoxy resins applicable for the presentinvention, publicly-known resins, for examples, bisphenolA-epichlorohydrin resin, multifunctional epoxy resins, alicyclic epoxyresins, brominated epoxy resins, and epoxy-novolac resins, which containat least one epoxy group in the molecule, can be given.

The present invention is directed to an epoxy resin compositioncharacterized in that the composition contains a clathrate comprising atetrakisphenol compound represented by a general formula [1] and eithera curative for epoxy resins or a curing accelerator for epoxy resins,such as amines and imidazoles as described above, as a curative forepoxy resins and/or a curing accelerator for epoxy resins.

The amount of the clathrate to be used may be same to the amount ofcuratives and curing accelerators commonly-used, such as amines andimidazoles, to prepare a clathrate, and it depends on a method forcuring. In case of using addition-type curatives of which molecules arealways contained in the cured-resin because of its reaction with theepoxy groups, a clathrate is normally prepared by using a curative in anamount ranging from 0.3 to 1.0 mole relative to 1 mole of epoxy groups,though it depends on requirements on the property of a desired resin.Whereas, in case of polymerization-type curatives or lightinitiation-type curatives, which causes polymerization and additionreactions between oligomers by inducing the ring opening of epoxy groupsin a reagent fashion without causing the inclusion of the curativemolecules into the resin, and in case of using the clathrate as a curingaccelerator, the content of the clathrate can be sufficient even it isless than 0.2 mole relative to 1 mole of epoxy groups. Particularly inthe present invention, by using a clathrate wherein a tetrakisphenolcompound is used, it is possible to reduce the content of the clathrateto a small amount ranging from 0.001 to 0.1 mole, and further to a rangeof from 0.001 to 0.05 mole. Further, it is also possible to use suchclathrates as single or by mixing 2 or more thereof.

When the curative for epoxy resins or the curing accelerator for epoxyresins comprising the clathrate according to the present invention iscompounded with the uncured epoxy resin as described above, the thermalstability which is very important for the control of a curing reactionis remarkably improved when compared with the stability of the epoxyresin, wherein only the guest compound (a curative or a curingaccelerator, such as amines and imidazoles, before being included)contained in the curative and the curing accelerator is compounded.

The curative for epoxy resins and the curing accelerator for epoxyresins according to the present invention have good resistance againsthumidity and does not cause the decomposition and sublimation thereof.

And, the resin compositions according to the present inventioncontaining the clathrates as a curatives or a curing accelerator asdescribed above have several excellent thermal properties. For thethermal properties of the resin composition, three properties, includingthe thermal stability at an ordinary temperature (stability as aone-pack mixture), thermal stability to heating at a temperature of froman ordinary temperature to a desired temperature for a curing reactionand thermal stability at a curing temperature, are required, The uncuredepoxy resins compounded with the curative and the curing acceleratoraccording to the present invention are very stable (having goodstability as a one-pack mixture) under an ordinary temperature and arecurable by just heating them up to a certain temperature to promptlyproduce a cured-product. The curing of the epoxy resin should not beinitiated at a temperature below 80° C. or around. However, the epoxyresin starts curing rapidly when temperature raised to a range of from100 to 130° C., which is normally desired for curing. In case of usingknown curatives and curing accelerators, curing of epoxy resins normallystart gradually by heating even before a time that temperature reachesto a desired range for curing, which gives unfavorable effect to thecured-product. In addition, in case of using a known curative havingrelatively excellent thermal stability, the initiating temperature forcuring comes into a higher range of from 150 to 180° C. However, byusing the curative according to the present invention, curing at a lowerrange of temperature can be done.

As described above, the present invention discloses that atetrakisphenol compound and a curative for epoxy resins or a curingaccelerator for epoxy resins produce a crystalline clathrate havingexcellent preserving property and that the epoxy resin compositioncontaining the said clathrate has remarkably excellent thermal property.

Further, the tetrakisphenol compound that forms the said clathrate is acompound that is conventionally known as an addition-type curative.

However, the inventors of the present invention found that thetetrakisphenol compound itself has an excellent catalytic action forcuring epoxy resins.

Therefore, the present invention is also understood that it is directedto an epoxy resin composition comprising a curative which reacts withthe epoxy group of an epoxy resin to cure the resins and atetrakisphenol compound represented by a general formula [I] in anamount of from 0.001 to 0.1 mole based on 1 mole of the epoxy groups;

wherein X represents (CH₂)n, wherein n is 0, 1, 2 or 3, and R¹ to R⁸each represents hydrogen, a lower alkyl, optionally-substituted phenyl,halogeno or a lower alkoxy.

Examples for both of the curatives used in the present invention and thetetrakisphenol compounds represented by a general formula [I] and usedtogether with the curatives are as described above.

By using the epoxy resin composition according to the present inventioncontaining a tetrakisphenol compound, various curing reactions canproceed faster and smoothly even under a mild condition, which allow toobtain stable cured-products, because of the excellent catalyticactivity of a tetrakisphenol compound for curing epoxy resins, and thecuring property of a resin composition can be extremely improved byusing the inventive epoxy resin composition when compared to the curingby using a curative only.

As described above, by using the clathrate comprising a curative forepoxy resins, such as amine compounds and imidazole compounds, and atetrakisphenol compound, as a curative for epoxy resins, it is allowedto obtain a resin compound which has excellent thermal properties, suchas stability as a one-pack mixture, stability to heat and curability ata low temperature, even with a very small amount, because of doubleeffects, that is release of the curative included in the clathrate byheating and demonstration of concurrent catalytic effect given by thetetrakisphenol compound.

In addition to the elements described above, it is also allowable tocompound various additives, such as a plasticizer, an organic solvent, areactive diluent, a filler, a bulking agent, a reinforcing agent, apigment, a flame retardant, a thickener and a mold-releasing agent, intothe epoxy resin composition of the present invention, if required.

The curative for epoxy resins and the curing accelerator for epoxyresins specified in the present invention can be suitably used forcuring epoxy resins, such as for epoxy resin-type adhesives, sealantsfor semiconductors, laminates for printed boards, varnish, powderpaints, casting materials and inks.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 10) described in Table 1.

FIG. 2 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 11) described in Table 1.

FIG. 3 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 19) described in Table 1.

FIG. 4 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 20) described in Table 1.

FIG. 5 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 21) described in Table 1.

FIG. 6 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 22) described in Table 1.

FIG. 7 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 23) described in Table 1.

FIG. 8 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 24) described in Table 1.

FIG. 9 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 27) described in Table 2.

FIG. 10 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 28) described in Table 2.

FIG. 11 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 29) described in Table 2.

FIG. 12 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 30) described in Table 2.

FIG. 13 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 31) described in Table 2.

FIG. 14 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 32) described in Table 2.

FIG. 15 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 33) described in Table 2.

FIG. 16 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 38) described in Table 2.

FIG. 17 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 43) described in Table 2.

FIG. 18 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 46) described in Table 2.

FIG. 19 shows a thermal analysis chart (TG/DTA) of a clathrate (SampleNo. 47) described in Table 2.

FIG. 20 shows a ¹HNMR spectrum chart of a clathrate (Sample No. 10)described in Table 1.

FIG. 21 shows a ¹HNMR spectrum chart of a clathrate (Sample No. 21)described in Table 1.

FIG. 22 shows a ¹HNMR spectrum chart of a clathrate (Sample No. 24)described in Table 1.

FIG. 23 shows a ¹HNMR spectrum chart of a clathrate (Sample No. 27)described in Table 2.

FIG. 24 shows a ¹HNMR spectrum chart of a clathrate (Sample No. 28)described in Table 2.

FIG. 25 shows an IR spectrum chart of a clathrate (Sample No. 24)described in Table 1.

FIG. 26 shows an IR spectrum chart of a clathrate (Sample No. 27)described in Table 2.

FIG. 27 shows an IR spectrum chart of a clathrate (Sample No. 39)described in Table 2.

FIG. 28 shows an IR spectrum chart of a clathrate (Sample No. 42)described in Table 2.

FIG. 29 shows an IR spectrum chart of a clathrate (Sample No. 45)described in Table 2.

FIG. 30 shows a X-ray diffraction pattern of a clathrate (Sample No. 10)described in Table 1.

FIG. 31 shows a X-ray diffraction pattern of a clathrate (Sample No. 27)described in Table 2.

FIG. 32 shows a X-ray diffraction pattern of a clathrate (Sample No. 31)described in Table 2.

FIG. 33 shows a ¹³C solid NMR spectrum chart of a clathrate (Sample No.24) described in Table 1.

FIG. 34 shows a ¹³C solid NMR spectrum chart of a clathrate (Sample No.27) described in Table 2.

FIG. 35 shows a ¹³C solid NMR spectrum chart of a clathrate (Sample No.28) described in Table 2.

FIG. 36 shows a ¹³C solid NMR spectrum chart of a clathrate (Sample No.30) described in Table 2.

FIG. 37 shows a result of X-ray single crystal structure analysis of aclathrate (Sample No. 10) described in Table 1.

FIG. 38 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 48) described in Table 3.

FIG. 39 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 49) described in Table 3.

FIG. 40 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 51) described in Table 3.

FIG. 41 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 52) described in Table 3.

FIG. 42 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 53) described in Table 3.

FIG. 43 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 54) described in Table 3.

FIG. 44 shows a thermal analysis (TG/DTA) chart of a compound (SampleNo. 55) described in Table 3.

FIG. 45 shows a ¹HNMR spectrum chart of a compound (Sample No. 49)described in Table 3.

FIG. 46 shows a ¹HNMR spectrum chart of a compound (Sample No. 53)described in Table 3.

FIG. 47 shows a ¹HNMR spectrum chart of a compound (Sample No. 54)described in Table 3.

FIG. 48 shows a result of measurements of a prolonged pot life(viscosity) of the resin compositions which are using the sample No. 32specified in Example 2 and the samples No. 53 and No. 54 specified inComparison Example 2 described below, respectively.

FIG. 49 shows a result of measurements of a prolonged pot life(viscosity) of the resin compositions which are using the sample No. 24specified in Example 3 and the sample No. 50 specified in ComparisonExample 3 described below, respectively.

FIG. 50 shows a result of measurements of a prolonged pot life(viscosity) of the resin compositions which are using the samples No. 10and No. 11 specified in Example 4 and the samples No. 48 and No. 49specified in Comparison Example 4 described below, respectively.

FIG. 51 shows a result of measurements of a prolonged pot life(viscosity) of the resin compositions which are using the samples No. 36and No. 38 specified in Example 5 and the sample No. 55 specified inComparison Example 5 described below, respectively.

FIG. 52 shows a result of measurements of a prolonged pot life(viscosity) of the resin compositions which are using the samples No. 27and No. 28 specified in Example 6 and 1B2MZ specified in ComparisonExample 6 described below, respectively.

FIG. 53 shows a DSC chart of the resin composition containing the sampleNo. 32, which is specified in Example 7 described below.

FIG. 54 shows a DSC chart of the resin composition containing the sampleNo. 33, which is specified in Example 7 described below.

FIG. 55 shows a DSC chart of the resin composition containing the sampleNo. 53, which is specified in Comparison Example 7 described below.

FIG. 56 shows a DSC chart of the resin composition containing the sampleNo. 54, which is specified in Comparison Example 7 described below.

FIG. 57 shows a DSC chart of the resin composition containing the sampleNo. 24, which is specified in Example 8 described below.

FIG. 58 shows a DSC chart of the resin composition containing the sampleNo. 50, which is specified in Comparison Example 8 described below.

FIG. 59 shows a DSC chart of the resin composition containing the sampleNo. 10, which is specified in Example 9 described below.

FIG. 60 shows a DSC chart of the resin composition containing the sampleNo. 11, which is specified in Example 9 described below.

FIG. 61 shows a DSC chart of the resin composition containing the sampleNo. 48, which is specified in Comparison Example 9 described below.

FIG. 62 shows a DSC chart of the resin composition containing the sampleNo. 49, which is specified in Comparison Example 9 described below.

FIG. 63 shows a DSC chart of the resin composition containing the sampleNo. 36, which is specified in Example 10 described below.

FIG. 64 shows a DSC chart of the resin composition containing the sampleNo. 38, which is specified in Example 10 described below.

FIG. 65 shows a DSC chart of the resin composition containing the sampleNo. 55, which is specified in Comparison Example 10 described below.

FIG. 66 shows a DSC chart of the resin composition containing the sampleNo. 56, which is specified in Comparison Example 10 described below.

FIG. 67 shows a DSC chart of the resin composition containing the sampleNo. 27, which is specified in Example 11 described below.

FIG. 68 shows a DSC chart of the resin composition containing the sampleNo. 28, which is specified in Example 11 described below.

FIG. 69 shows a ¹HNMR spectrum chart of the sample No. 38 specified inExample 14 after subjecting it to a moisture absorption test.

FIG. 70 shows a ¹HNMR spectrum chart of the sample No. 56 specified inComparison Example 13 after subjecting it to a moisture absorption test.

FIG. 71 shows a DSC chart of the resin composition containing the sampleNo. 27 specified in Example 19 after subjecting it to a heating test.

FIG. 72 shows a DSC chart of the resin composition containing 1B2MZspecified in Comparison Example 18 after subjecting it to a heatingtest.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the present invention is further described in detail with referringthe examples as shown below, however, it should be noted that thepresent invention shall not be limited to the scope being described inthe examples below.

EXAMPLE 1 Manufacturing of Clathrates

Clathrates were prepared by using various curatives, curing acceleratorsand tetrakisphenol-containing host compounds according to either themethod (1) or the method (2) as described below. (1) When a curative ora curing accelerator is in liquid sate under a room temperature, 10parts by weight of either the curative or the curing accelerator wasadded with 1 part of a host compound and was subsequently stirred for 1to 120 min. under a temperature of from 25 to 100° C., and the mixturewas then allowed to stand for 1-48 hours to precipitate the crystals.After taking out the crystals by filtration, the crystals were driedunder reduced pressure at a temperature of from a room temperature to80° C. to obtain the clathrate according to the present invention.Whereas, when a curative or a curing accelerator is in solid state, itwas mixed with a host compound at a specific mole ratio, and the mixturewas then kneaded in a mortar for one hour to obtain the clathrateaccording to the present invention. The method to prepare the clathratesas described above by directly mixing either a curative or a curingaccelerator and a host compound is hereinafter simplified by using aterm “Neat”. (2) Either a curative or a curing accelerator was dissolvedin a solvent selected from methanol, ethyl acetate and dichloromethane,and a host compound in an amount of from 0.1 to an equivalent mole ratiorelative to the amount of either the curative or the curing acceleratorwas added into the resultant solution and then dissolved or suspended inthe mixture while heating at a temperature ranging from a roomtemperature to the reflux temperature of a solvent used. Then, themixture was stirred for 1-120 min. and was allowed to stand for 1-48hours at room temperature to precipitate the crystals. After taking outthe crystals by means of filtration, the crystals were dried underreduced pressure to obtain the clathrate according to the presentinvention. The results during the preparation of the clathrates werepresented in Tables 1 and 2. All samples of the clathrates obtainedaccording to the processes described in the examples were determined asthe objective clathrates by means of measuring IR spectrums. NMRspectrums, and thermal analysis (TG*DTA and/or DSC) and powder X-raydiffraction pattern analysis. The abbreviations in Tables 1 and 2represent respectively any of a curative, a curing accelerator or a hostcompound as described in the following.

Curatives and Curing accelerators:

DEA: Diethylamine

TEA: Triethylamine

PRI: Piperidine

PRA: Piperazine

PY: Pyridine

EDA: Ethylenediamine

TMDA Trimethylenediamine

TEMDA: Tetramethylenediamine

HMDA: Hexamethylenediamine

DETA: Diethylenetriamine

TEDA: Triethylenediamine

o-PDA: Ortho-phenylenediamine

m-PDA: Meta-phenylenediamine

p-PDA: Para-phenylenediamine

BMAEE: Bis(2-dimethylaminoethyl)ether

DMAH: N,N-dimethylaminohexanol

TMHM: N,N,N′,N′-tetramethylhexamethylenediamine

2E4MZ: 2-Ethyl-4-methylimidazole

1B2MZ: 1-Benzyl-2-methylimidazole

1I2MZ: 1-Isopropyl-2-methylimidazole

2MZ: 2-Methylimidazole

2PZ: 2-Phenylimidazole

2PZL: 2-Phenylimidazoline

DBU: 1,8-Diazabicyclo(5,4,0)undecene

Host compounds:

TEP: 1,1,2,2-Tetrakis(4-hydroxyphenyl)ethane

TEOC: 1,1,2,2-Tetrakis(3-methyl-4-hydroxyphenyl)ethane

TDOC: 1,1,2,2-Tetrakis(3,5-dimethyl-4-hydroxyphenyl)ethane

TCOC: 1,1,2,2-Tetrakis(3-chloro-4-hydroxyphenyl)ethane

TABLE 1 Curative-Releasing Curative/Curing Host Compound Solvent forClathrate Composition Temperature of Sample No. Accelerator (G) (H)Preparing Clathrate H:G:Solvent (Mole ratio) Clathrate (° C.) 1 DEA TEPNeat 1:2:0 119 2 DEA TEOC Neat 1:2:0 90 3 TEA TEP Neat 1:1:0 116 4 TEATEOC Neat 1:2:0 108 5 PRI TEP Neat 1:2:0 174 6 PRA TEP Neat 1:2:0 162 7PY TEP Neat 1:4:0 112 8 PY TEOC Neat 1:5:0 55 9 PY TCOC Neat 1:3:0 73 10EDA TEP Methanol 1:1:0 202 11 EDA TEOC Methanol 1:1:0 182 12 EDA TDOCMethanol 1:1:0 161 13 TMDA TEP Neat 1:1:5:0 190 14 TEMDA TEP Neat 1:2:0202 15 HMDA TEP Neat 1:1:0 160 16 DETA TEP Neat 1:2:0 133 17 o-PDA TEPEthyl-acetate 1:5:0 147 18 m-PDA TEP Methanol 1:2:0 75 19 p-PDA TEPMethanol 1:3:0 176 20 p-PDA TEP Ethyl acetate 1:2:0 172 21 BMAEE TEPEthyl acetate 1:2:0 141 22 DMAH TEP Ethyl acetate 1:1:1 183 23 TMHM TEPMethanol 1:1:0 186 24 2E4MZ TEP Methanol 1:2:0 187

TABLE 2 Curative-Releasing Curative/Curing Host Compound Solvent forClathrate Composition Temperature of Sample No. Accelerator (G) (H)Preparing Clathrate H:G:Solvent (Mole ratio) Clathrate (° C.) 25 2E4MZTEP Ethyl acetate 1:1.5:0 191 26 1B2MZ TEP Neat 1:6:0 143 27 1B2MZ TEPMethanol 1:2:0 200 28 1B2MZ TEOC Methanol 1:4:0 168 29 1B2MZ TEOC Neat1:4:0 162 30 1B2MZ TDOC Methanol 1:0.5:0 173 31 1I2MZ TEP Methanol 1:2:0183 32 2MZ TEP Ethyl acetate 1:2:1 175 33 2MZ TEOC Dichloromethane 1:2:1147 34 2PZ TEP Methanol 1:1.5:0.5 227 35 2PZL TEP Methanol 1:2:2 216 362PZL TEP Ethyl acetate 1:2:0 207 37 2PZL TEOC Methanol 1:2:2 201 38 2PZLTEOC Ethyl acetate 1:2:0 178 39 DBU TEP Methanol 1:1.5:0 >240 40 DBU TEPEthyl acetate 1:2:0 183 41 DBU TEP Dichtoromethane 1:1.5:0 >240 42 DBUTEOC Methanol 1:2:0 >240 43 DBU TEOC Ethyl acetate 1:2:0 210 44 DBU TEOCDlchloromethane 1.2:0 >240 45 DBU TDOC Methanol 1:2:0 147 46 DBU TDOCEthyl acetate 1:2:1 179 47 DBU TDOC Dichloromethane 1:2:0 180

From the samples described in Tables 1 and 2, the thermal analysis(TG/DTA) charts for the samples, Nos. 10, 11, 19, 20, 21, 22, 23, 24,27, 28, 29, 30, 31, 32, 33, 38, 43, 46 and 47, are shown in FIGS. 1through 19, respectively. Besides, ¹H NMR spectrums, wherein heavymethanol was used as a solvent, for the samples. Nos. 10, 21, 24, 27 and28, are shown in FIGS. 20 through 24, respectively. The IR spectrums forthe samples, Nos. 24, 27, 39, 42 and 45, are shown in FIGS. 25 through29, respectively. The powder X-ray diffraction patterns for the samples,Nos. 10, 27 and 31, are shown in FIGS. 30 through 32, respectively.Further, the ¹³C NMR spectrums for the samples, Nos. 24, 27, 28 and 30,are shown in FIGS. 33 through 36, respectively. Again, the result ofX-ray single crystal structure analysis for the sample No. 10 is shownin FIG. 37. Whereas, the results of X-ray single crystal structureanalysis for the samples, Nos. 19, 20, 28 and 31, have been obtained aswell, and the structures of those samples have been determined as onesbeing formed into molecular crystal structure wherein a host compoundand a guest compound are regularly configured in three dimensionaldirection same as the structure of the sample No. 10.

COMPARISON EXAMPLE 1 Manufacturing of Curatives and Curing AcceleratorsAccording to Conventional the Method

According to the method described in the patent previously disclosed,the manufacturing of curatives and curing accelerators were performed.The samples manufactured were shown in Table 3. The abbreviations forcuratives and curing accelerators shown in Table 3 are corresponding tothe compounds described in the examples, respectively.

The abbreviations for phenol compounds represent the followingcompounds, respectively.

BHC: 1,1-Bis(4-hydroxyphenyl)cyclohexane

BPA: Bisphenol A[2,2-bis(4-hydroxyphenyl)propane]

BPS: Bisphenol S(4,4′-dihydroxydiphenylsulfone)

Whereas, the references (1) through (5) shown in Table 3, which aredescribing the preparation method for the samples, correspond to thefollowing references, respectively.

(1) Japanese Patent Laid-open No. Hei 5-194711 Gazette

(2) U.S. Pat. No. 3,519,576

(3) U.S. Pat. No. 4,845,234 and Japanese Patent Publication No. Hei6-9868

(4) Japanese Patent Publication No. Sho 62-24006

(5) Japanese Patent Laid-open No. Hei 8-15142 Gazette

TABLE 3 Reference Describing Sample Composition Curative/ PreparationMethod of Curative:Phenol Compound Sample No. Curing Accelerator PhenolCompound Samples (Mole ratio) 48 EDA BHC (1) 1:1 49 EDA BPA (2) 1:1 502E4MZ BHC (1) 1:1 51 2E4MZ BPS (3) 1:1 52 1B2MZ BPS (3) 1:1 53 2MZ BHC(1) 1:1 54 2MZ BPA (1) 1:1 55 2PZL BPS (4) 1:1 56 2PZL BPS (5) 1:1

From the samples described in Table 3, the thermal analysis (TG/DTA)charts for the samples, Nos. 48, 49, 51, 52, 53, 54 and 55, are shown inFIGS. 38 through 44, respectively. Further, the ¹H NMR spectrumanalysis, wherein heavy methanol was used as a solvent, for the samples,Nos. 49, 53 and 54, are shown in FIGS. 45 through 47, respectively.

EXAMPLE 2 Measurement of Prolonged Pot Life of Resin Compositions (Part1)

To 100 parts of a base resin (uncured resin) UVR-6410 (Trade name,Manufactured by Union Carbide Co., Ltd.), was added 13.7 parts(corresponding to 4.0 parts by weight as 2MZ) of the inventive curative,sample No. 32, described in Table 1. The mixture was kneaded for 10 min.at 25° C. and was further allowed to stand for 20 min. at 25° C. Then,the initial viscosity of the resin composition prepared was measured.The resin composition was then placed under 25° C., and periodicalchange in viscosity was measured. The viscosity measurement was accordedto JIS K-6833-1994, and B8R-type rotational viscosity meter(Manufactured by Tokyo Keiki) was used for the measurement. The resultsof the measurement are shown in Table 4 and FIG. 48. When prolonged potlife of the resin composition is defined as the time requiring for theviscosity of a resin to be the double value of the initial viscosityvalue, the prolonged pot life was found to be 18 hours when using theinventive curative, sample No. 32.

COMPARISON EXAMPLE 2

To 100 parts of UVR-6410, was added 17.1 parts by weight (4.0 parts byweight based on 2MZ) of the curative, sample No. 53 described in Table3. According to the procedure as described in Example 2, the initialviscosity of the resulting resin composition and the periodical changein viscosity thereof were measured. In addition, measurement of theviscosity of the resin composition, wherein 15.1 parts by weight (4.0parts by weight based on 2MZ) of a curative having sample No. of 54described in Table 3 is contained instead of the curative of sample No.53, was also performed. The results are shown in Table 4 and FIG. 48.When using the curative of sample No. 53, the prolonged pot life of theresin composition was 9 hours, while the prolonged pot life of the resincomposition, wherein the curative of sample No. 54 is used, was 5 hours.

When compared the results each obtained in Example 2 and ComparisonExample 2, it is clearly demonstrated that the curative of the presentinvention can remarkably prolonged the pot life of the resin compositioncomparing to other compositions which are using curatives beingconventionally-used.

EXAMPLE 3 Measurement of Prolonged Pot Life of Resin Compositions (Part2)

To 100 parts of a base resin (uncured resin) UVR-6410 (Trade name,Manufactured by Union Carbide Co., Ltd.), was added 11.2 parts by weight(corresponding to 4.0 parts by weight as 2B4MZ) of the inventivecurative of sample No. 24 described in Table 1. Then, the viscosity ofthe resulting resin composition was measured according to the procedureas described in the example 2. The results of the measurement are shownin Table 5 and FIG. 49. When using the inventive curative of sample No.24, the prolonged pot life, which is the time required for the viscosityof the resin composition to be a double value of the initial viscosityvalue, was found to be 180 hours.

COMPARISON EXAMPLE 3

To 100 parts by weight of UVR-6410, was added 13.7 parts by weight(equivalent to 4.0 parts by weight based on 2E4MZ) of a curative ofsample No. 50. The viscosity of the resultant resin composition wasmeasured according to the procedure described in the example 2. Theresults are shown in Table 5 and FIG. 49. When using the curative ofExample No. 50 according to the method in the past, the prolonged potlife, which is the time required for the viscosity of the resincomposition to be a double value of the initial viscosity value, wasfound to be 12 hours.

From the comparison between the result in the example 3 and that of thecomparison example 3, it is obvious that the inventive curative canprolong the pot life of the resin compositions remarkably comparing tothat of other resin compositions using curatives conventionally-used.

TABLE 4 Viscosity of Resin Composition (cp/25° C.) Time ResinComposition Resin Composition Resin Composition (h) Sample No. 32 SampleNo. 53 Sample No. 54 0 40500 35100 37100 1 42800 35300 38700 2 3810044400 4 43000 41900 63900 6 48800 86000 8 44200 67900 94300 10 78000 1254300 94300 18 80500 24 149000

TABLE 5 Viscosity of Resin Composition (cp/25° C.) Resin CompositionResin Composition Time (h) Sample No. 24 Sample No. 50 0 19600 24800 119800 27400 2 29400 4 20100 29400 8 20700 37000 12 20900 48100 24 21900107000 36 22100 60 22500 132 23000 180 30600

EXAMPLE 4 Measurement of Prolonged Pot Life of Resin Compositions (Part3)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 30.5 parts byweight (corresponding to 4.0 parts by weight based on EDA) of theinventive curative of sample No. 10 described in Table 1. The viscosityof the resultant resin composition was measured according to theprocedure described in the example 2. Similarly, the viscositymeasurements were also done about a resin composition, in which 34.2parts by weight (equivalent to 4.0 parts by weight based on EDA) of acurative of sample No. 11 described in Table 1 was used instead of thecurative of sample No. 10. The results of the measurement are shown inTable 6 and FIG. 50. When using the curative of sample No. 10, theprolonged pot life, which is defined as time required for the viscosityof the resin to be a double value of the initial viscosity value, wasfound to be 180 hours. Whereas, when using the inventive curative ofsample No. 11, the prolonged pot life was more than 180 hours.

COMPARISON EXAMPLE 4

To 100 parts by weight of UVR-6410, was added 21.9 parts by weight(equivalent to 4.0 parts by weight based on EDA) of a curative of sampleNo. 48. The viscosity of the resultant resin composition was measuredaccording to the procedure described in the example 2. Similarly, theviscosity measurements were also done about a resin composition, inwhich 19.2 parts by weight (equivalent to 4.0 parts by weight based onEDA) of a curative of sample No. 49 described in Table 3 was usedinstead of the curative of sample No. 48. The results are shown in Table6 and FIG. 50. When using the curative of sample No. 48, the prolongedpot life, which is time required for the viscosity of the resincomposition to be a double value of the initial viscosity value, wasfound to be 6 hours. Whereas, when using the curative of sample No. 49,the prolonged pot life was 2 hours.

From the comparison between the result in the example 4 and that of thecomparison example 4, it is obvious that the inventive curative canprolong the pot life of the resin compositions remarkably comparing tothat of other resin compositions using curatives conventionally-used.

EXAMPLE 5 Measurement of Prolonged Pot Life of Resin Compositions (Part4)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 9.46 parts byweight (equivalent to 4.0 parts by weight based on 2PZL) of theinventive curative of sample No. 36 described in Table 1. The viscosityof the resultant resin composition was measured according to theprocedure described in the example 2. Similarly, viscosity measurementswere also done about a resin composition, in which 10.2 parts by weight(equivalent to 4.0 parts by weight based on 2PZL) of a curative ofsample No. 38 described in Table 1 was used instead of the curative ofsample No. 36. The results of the measurement are shown in Table 7 andFIG. 51. When using the curative of sample No. 36, the prolonged potlife, which is defined as time required for the viscosity of the resincomposition to be a double value of the initial viscosity value, wasfound to be 180 hours. Whereas, when using the inventive curative ofsample No. 38, the prolonged pot life was more than 180 hours.

COMPARISON EXAMPLE 5

To 100 parts by weight of UVR-6410, was added 15.1 parts by weight(equivalent to 4.0 parts by weight based on 2PZL) of a curative ofsample No. 55. The viscosity of the resultant resin composition wasmeasured according to the procedure described in the example 2. Theresults are shown in Table 7 and FIG. 51. When using the curative ofsample No. 55, the prolonged pot life, which is time required for theviscosity of the resin composition to be a double value of the initialviscosity value, was found to be 36 hours.

From the comparison between the result in the example 5 and that of thecomparison example 5, it is obvious that the inventive curative canprolong the pot life of the resin compositions remarkably comparing tothat of other resin compositions using curatives conventionally-used.

TABLE 6 Viscosity of Resin Composition (cp/25° C.) Resin Resin ResinResin Time Composition Composition Composition Composition (h) SampleNo. 10 Sample No. 11 Sample No. 48 Sample No. 49 0 52800 42000 4580030500 1 52800 42000 58200 44400 2 63700 68500 4 53000 43000 73800 1350006 94300 288000 8 53000 43200 106000 12 53400 43700 24 53400 43900 3653400 44900 60 55200 46600 132 62100 50100 180 109000 67900

TABLE 7 Viscosity of Resin Composition (cp/25° C.) Time ResinComposition Resin Composition Resin Composition (h) Sample No. 36 SampleNo. 38 Sample No. 55 0 40500 35100 37100 1 42800 35300 38700 2 3810044400 4 43000 41900 63900 6 48800 86000 8 44200 67900 94300 10 78000 1254300 94300 24 80500 36 149000

EXAMPLE 6 Measurement of Prolonged Pot Life of Resin Compositions (Part5)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.). was added 8.62 parts byweight (equivalent to 4.0 parts by weight based on 1B2MZ) of theinventive curative of sample No. 27 described in Table 1. The viscosityof the resultant resin composition was measured according to theprocedure described in the example 2. Similarly, viscosity measurementswere also done about a resin composition, in which 6.64 parts by weight(equivalent to 4.0 parts by weight based on 1B2MZ) of a curative ofsample No. 28 described in Table 1 was used instead of the curative ofsample No. 27. The results of the measurement are shown in Table 8 andFIG. 52. When using the curative of sample No. 27, the prolonged potlife, which is defined as time required for the viscosity of the resincomposition to be a double value of the initial viscosity value, wasfound to be 60 hours. Whereas, when using the inventive curative ofsample No. 28, the prolonged pot life was 36 hours.

COMPARISON EXAMPLE 6

To 100 parts by weight of UVR-6410, was added 4.0 parts by weight(equivalent to 4.0 parts by weight based on 1B2MZ) of a curative ofsample No. 55. The viscosity of the resultant resin composition wasmeasured according to the procedure described in the example 2. Theresults are shown in Table 8 and FIG. 52. When using 1B2MZ, theprolonged pot life, which is time required for the viscosity of theresin composition to be a double value of the initial viscosity value,was found to be 10 hours.

From the comparison between the result in the example 6 and that of thecomparison example 6, it is obvious that the pot life of the resincompositions can be prolonged remarkably by means of using the inventivecuratives.

TABLE 8 Viscosity of Resin Composition (cp/25° C.) Resin CompositionTime Resin Composition Resin Composition Compounded (h) Sample No. 27Sample No. 28 with 1B2MZ 0 17300 19600 10200 1 17300 20000 10200 2 107004 17400 22300 12400 6 14800 8 17400 22800 16700 10 20400 12 17800 2530027100 24 23700 25300 689000 36 28500 34500 48 35000 35100 60 52000 7890084 392000 132 20700 180

EXAMPLE 7 Measurement of Curing Temperature of Resin Compositions (Part1)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 13.7 parts byweight (equivalent to 4.0 parts by weight based on 2MZ) of the inventivecurative of sample No. 32 described in Table 1. After kneading theresulting resin composition for 10 min. at 25° C., the part thereof wascollected and its curing temperature was determined by measuring theheat generated from the resin composition during the curing reaction byusing a differential scanning calorimeter (DSC) under nitrogen gas flowat 30 ml/min. and at a temperature elevation rate of 10° C./min. As aresult, it was found that the curing initiation temperature of the resincomposition was 93° C. and the peak of heat generated during thereaction was 140° C. The DSC chart of the resin composition is shown inFIG. 53. Similarly, DSC measurements were also made for a resincomposition, wherein 15.1 parts by weight (equivalent to 4.0 parts byweight based on 2MZ) of a curative of sample No. 33 is used instead ofthe curative of sample No. 32, and it was demonstrated that the curinginitiation temperature of the later resin composition was 90° C. and thepeak of heat generated during the reaction was 126° C. The DSC chart ofthe later resin composition is shown in FIG. 54.

COMPARISON EXAMPLE 7

To 100 parts by weight of UVR-6410, was added 17.1 parts by weight(equivalent to 4.0 parts by weight based on 2MZ) of a curative of sampleNo. 53 described in Table 3. The curing temperature of the resultingresin composition was measured according to the procedure described inthe example 7. As a result, it was found that the curing initiationtemperature of the resin composition was 79° C. and the peak of heatgenerated during the reaction was 126° C. The DSC chart of the resincomposition is shown in FIG. 55. Similarly, DSC measurements were alsomade for a resin composition, wherein 15.1 parts by weight (equivalentto 4.0 parts by weight based on 2MZ) of a curative of sample No. 54 wasused instead of the curative of sample No. 53, and it was demonstratedthat the curing initiation temperature of the later resin compositionwas 71° C. and the peak of heat generated during the reaction was 122°C. The DSC chart of the later resin composition is shown in FIG. 56.

From the comparison between the result in the example 7 and that of thecomparison example 7, it was shown that the thermal stability of theresin compositions using a curative conventionally-used, the sample Nos.53 or 54, was damaged, because the curing reaction has already startedfrom a low temperature lower than 80° C. On the other hand, both resincompositions using a curative of sample No. 32 or No. 33 according tothe present invention have a curing initiation temperature higher than90° C., respectively, and it is obviously understood that the thermalstability of the inventive resin compositions are well secured and theinventive curatives have excellent curing activity at a favorabletemperature range of from 125 to 140° C.

EXAMPLE 8 Measurement of Curing Temperature of Resin Compositions (Part2)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 11.2 parts byweight (equivalent to 4.0 parts by weight based on 2E4MZ) of theinventive curative of sample No. 24 described in Table 1. The curingtemperature of the resulting resin composition was measured according tothe procedure described in the example 7. As a result, it was found thatthe curing initiation temperature of the resin composition was 125° C.and the peak of heat generated during the reaction was 146° C. The DSCchart of the resin composition is shown in FIG. 57.

COMPARISON EXAMPLE 8

To 100 parts by weight of UVR-6410, was added 13.7 parts by weight(equivalent to 4.0 parts by weight based on 2E4MZ) of a curative ofsample No. 50 described in Table 3. The curing temperature of theresulting resin composition was measured according to the proceduredescribed in the example 7. As a result, it was found that the curinginitiation temperature of the resin composition was 80° C. and the peakof heat generated during the reaction was 130° C. The DSC chart of theresin composition is shown in FIG. 58.

From the comparison between the result in the example 8 and that of thecomparison example 8, it is shown that the thermal stability of theresin composition using a curative of sample No. 50 conventionally-usedwas damaged, because the curing reaction had already started from a lowtemperature of 80° C. On the other hand, the resin compositions usingthe curative of sample No. 24 according to the present invention have acuring initiation temperature higher than 90° C., and it is obviouslyunderstood that the thermal stability of the inventive resincompositions is well secured and the inventive curative has an excellentcuring activity at a favorable temperature of approximately 145° C.

EXAMPLE 9 Measurement of Curing Temperature of Resin Compositions (Part3)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 30.5 parts byweight (equivalent to 4.0 parts by weight based on EDA) of the inventivecurative of sample No. 10 described in Table 1. The curing temperatureof the resulting resin composition was measured according to theprocedure described in the example 7. As a result, it was found that thecuring initiation temperature of the resin composition was 117° C. andthe peak of heat generated during the reaction was 165° C. The DSC chartof the resin composition is shown in FIG. 59. Similarly, measurements ofcuring temperature were also made for a resin composition, wherein 34.2parts by weight (equivalent to 4.0 parts by weight based on EDA) of acurative of sample No. 11 described in Table 1 was used instead of thecurative of sample No. 10, and it was demonstrated that the curinginitiation temperature of the later resin composition was 104° C. andthe peak of heat generated during the reaction was 150° C. The DSC chartof the later resin composition is shown in FIG. 60.

COMPARISON EXAMPLE 9

To 100 parts by weight of UVR-6410, was added 21.9 parts by weight(equivalent to 4.0 parts by weight based on EDA) of a curative of sampleNo. 48 described in Table 3. The curing temperature of the resultingresin composition was measured according to the procedure described inthe example 7. As a result, it was found that the curing initiationtemperature of the resin composition was 65° C. and the peak of heatgenerated during the reaction was 97° C. The DSC chart of the resincomposition is shown in FIG. 61. Similarly, measurements of curingtemperature were also made for a resin composition, wherein 19.2 partsby weight (equivalent to 4.0 parts by weight based on EDA) of a curativeof sample No. 49 described in Table 3 was used instead of the curativeof sample No. 48, and it was demonstrated that the curing initiationtemperature of the later resin composition was 51° C. and the peak ofheat generated during the reaction was 81° C. The DSC chart of the laterresin composition is shown in FIG. 62.

From the comparison between the result in the example 9 and that of thecomparison example 9, it is shown that the thermal stability of bothresin compositions using curatives conventionally-used, the sample Nos.48 and 49, respectively, was damaged, because the curing reactions hadalready started from a low temperature lower than 65° C. On the otherhand, both resin compositions using the curatives of sample Nos. 10 and11 according to the present invention have a curing initiationtemperature higher than 90° C., respectively, and it is obviouslyunderstood that the thermal stability of the inventive resincompositions are well secured and the inventive curatives have excellentcuring activity at a favorable temperature range of from 150 to 165° C.

EXAMPLE 10 Measurement of Curing Temperature of Resin Compositions (Part4)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 9.46 parts byweight (equivalent to 4.0 parts by weight based on 2PZL) of theinventive curative of sample No. 36 described in Table 1. The curingtemperature of the resulting resin composition was measured according tothe procedure described in the example 7. As a result, it was found thatthe curing initiation temperature of the resin composition was 100° C.and the peak of heat generated during the reaction was 136° C. The DSCchart of the resin composition is shown in FIG. 63. Similarly,measurements of curing temperature were also made for a resincomposition, wherein 10.2 parts by weight (equivalent to 4.0 parts byweight based on 2PZL) of a curative of sample No. 38 described in Table1 was used instead of the curative of sample No. 36, and it wasdemonstrated that the curing initiation temperature of the later resincomposition was 93° C. and the peak of heat generated during thereaction was 129° C. The DSC chart of the later resin composition isshown in FIG. 64.

COMPARISON EXAMPLE 10

To 100 parts by weight of UVR-6410, was added 15.1 parts by weight(equivalent to 4.0 parts by weight based on 2PZL) of a curative ofsample No. 55 described in Table 3. The curing temperature of theresulting resin composition was measured according to the proceduredescribed in the example 7. As a result, it was found that the curinginitiation temperature of the resin composition was 79° C. and the peakof heat generated during the reaction was located at three points of114° C., 160° C. and 193° C. The DSC chart of the resin composition isshown in FIG. 65. Similarly, measurements of curing temperature werealso made for a resin composition, wherein a curative of sample No. 56was used instead of the curative of sample No. 55, and it wasdemonstrated that the curing initiation temperature of the later resincomposition was 85° C. and the peak of heat generated during thereaction was located at two points of 130° C. and 202° C. The DSC chartof the later resin composition is shown in FIG. 66.

From the comparison between the result in the example 10 and that of thecomparison example 10, it is shown that the thermal stability of bothresin compositions using curatives conventionally-used, the sample Nos.55 and 56, respectively, was damaged, because the curing reactions hadalready started from a low temperature lower than 85° C. On the otherhand, both resin compositions using the curatives of sample Nos. 36 and38 according to the present invention have a curing initiationtemperature higher than 90° C. respectively, and it is obviouslyunderstood that the thermal stability of the inventive resincompositions are well secured and the inventive curatives have excellentcuring activity at a favorable temperature range of from 130 to 135° C.

EXAMPLE 11 Measurement of Curing Temperature of Resin Compositions (Part5)

To 100 parts by weight of a base resin (uncured resin) UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), was added 8.62 parts byweight (equivalent to 4.0 parts by weight based on 1B2MZ) of theinventive curative of sample No. 27 described in Table 1. The curingtemperature of the resulting resin composition was measured according tothe procedure described in the example 7. As a result, it was found thatthe curing initiation temperature of the resin composition was 115° C.and the peak of heat generated during the reaction was 131° C. The DSCchart of the resin composition is shown in FIG. 67. Similarly,measurements of curing temperature were also made for a resincomposition, wherein 6.64 parts by weight (equivalent to 4.0 parts byweight based on 1B2MZ) of a curative of sample No. 28 described in Table1 was used instead of the curative of sample No. 27, and it wasdemonstrated that the curing initiation temperature of the later resincomposition was 110° C. and the peak of heat generated during thereaction was 127° C. The DSC chart of the later resin composition isshown in FIG. 68.

The inventive curatives of sample Nos. 27 and 28 have a curinginitiation temperature higher than 110° C. respectively, and it isobviously understood that the thermal stability of the resincompositions are well secured by using the inventive curatives and thecuratives have excellent curing effect on resin compositions at afavorable temperature ranging from 130 to 140° C.

EXAMPLE 12 Measurements of Hygroscopy of Curatives (Part 1)

2 g of a curative powder of sample No. 24 according to the presentinvention was placed in a petri dish having a diameter of 3 cm, and thesample was allowed to stand for 3 days under a temperature of 40° C. and90% R.H., and subsequently for 2 days under a temperature of 50° C. and90% R.H. During these days, the weight of the sample was measured every2 days to check the hygroscopy of the sample curative. The results areshown in Table 9. It is found that the curative has no hygroscopicproperty even under high humid atmosphere.

COMPARISON EXAMPLE 11

2 g of a curative powder of sample No. 51 described in Table 3 wasplaced in a petri dish having a diameter of 3 cm, and the hygroscopy ofthe sample was measured according to the procedure described in theexample 12. The results are shown in Table 9. The curative showed itshygroscopic property of approximately 6% by weight after 3 days layingunder an atmosphere of 40° C. and 90% R.H. Further, the sample showedits hygroscopic property of approximately 10% by weight when it wasplaced for 2 days under an atmosphere of 50° C. and 90% R.H.

From the comparison between the result in the example 12 and that of thecomparison example 11, it is shown that the curative of sample No. 51conventionally-used showed remarkable hygroscopic property after layingit under high humid atmosphere, while it is obviously understood thatthe inventive curative of sample No. 24 shows no hygroscopic propertyunder the same condition and that the inventive curative has anexcellent property of storage stability.

EXAMPLE 13 Measurements of Hygroscopy of Curatives (Part 2)

2 g of a curative powder of sample No. 10 according to the presentinvention was placed in a petri dish having a diameter of 3 cm, and thehygroscopy of the curative was determined according to the proceduredescribed in the example 12. Similarly, measurements of hygroscopy werealso made for the curative of sample No. 11 according to the sameprocedure. The results are shown in Table 10. It is found that thesecuratives showed to have no hygroscopic property even under high humidatmosphere.

COMPARISON EXAMPLE 12

2 g of a curative powder of sample No. 48 described in Table 3 wasplaced in a petri dish having a diameter of 3 cm, and the hygroscopy ofthe sample was measured according to the procedure described in theexample 12. Similarly, measurements of hygroscopy were also made for thecurative of sample No. 49 according to the same procedure. The resultsare shown in Table 10. The curative of sample No. 48 showed itshygroscopic property of approximately 5% by weight after 2 days layingunder an atmosphere of 50° C. and 90% R.H., whereas the curative ofsample No. 49 showed its hygroscopic property of approximately 25% byweight when it was placed for 3 days under an atmosphere of 40° C. and90% R.H. or approximately 60% by weight when it was placed for 2 daysunder an atmosphere of 50° C. and 90% R.H.

From the comparison between the result in the example 13 and that of thecomparison example 12, it is shown that the curatives of sample Nos. 48and 49 conventionally-used showed remarkable hygroscopic property afterlaying them under high humid atmosphere, respectively, while it isobviously understood that the inventive curatives of sample Nos. 10 and11 showed no hygroscopic property under the same condition and they havean excellent property of storage stability, respectively.

TABLE 9 Test Period Test Change in Weight (wt %) ‡ (Days) ConditionCurative Sample No. 24 Curative Sample No. 51 0 0 0 1 40° C. −0.03 3.332 R.H. 90% 0.01 4.97 3 0 5.85 4 50° C. −0.02 8.45 5 R.H. 90% −0.01 9.68‡ Change in Weight (wt %) = {[(Weight of Curative after Testing) −(Weight of Curative before Testing)] / (Weight of Curative beforeTesting) } × 100

TABLE 10 Change in Weight (wt %) ‡ Curative Curative Curative CurativeTest Period Test Sample Sample Sample Sample (Days) Condition No. 10 No.11 No. 48 No. 49 0 0 0 0 0 1 40° C. 0.12 −0.20 4.69 29.3 2 R.H. 90% 0.15−0.20 4.63 26.9 3 0.15 −0.17 4.57 24.6 4 50° C. 0.26 −0.18 5.30 52.8 5R.H. 90% 0.26 −0.18 5.15 57.7 ‡ Change in Weight (wt %) = {[(Weight ofCurative after Testing) − (Weight of Curative before Testing)] / (Weightof Curative before Testing) } × 100

EXAMPLE 14 Measurements of Hygroscopy of Curatives (Part 3)

2 g of a curative powder of sample No. 36 according to the presentinvention was placed in a petri dish having a diameter of 3 cm, and thehygroscopy of the curative was determined according to the proceduredescribed in the example 12. Similarly, measurements of hygroscopy werealso made for the curative of sample No. 38 according to the sameprocedure. The results are shown in Table 11. It is found that thesecuratives showed to have no hygroscopic property even under high humidatmosphere.

COMPARISON EXAMPLE 13

2 g of a curative powder of sample No. 56 described in Table 3 wasplaced in a petri dish having a diameter of 3 cm, and the hygroscopy ofthe curative was measured according to the procedure described in theexample 12, and the results are shown in Table 11. The curative showedits hygroscopic property of approximately 5% by weight after 3 dayslaying under an atmosphere of 40° C. and 90% R.H. or approximately 6% byweight when it was placed for 2 days under an atmosphere of 50° C. and90% R.H.

From the comparison between the result in the example 14 and that of thecomparison example 13, it is shown that the curative of sample No. 56conventionally-used showed remarkable hygroscopic property after layingthem under high humid atmosphere, while it is obviously understood thatthe inventive curatives of sample Nos. 36 and 38 showed no hygroscopicproperty under the same condition and they have an excellent property ofstorage stability, respectively.

Further, after performing the test above, ¹H NMR spectrum analysis wascarried out for the curatives of sample Nos. 38 and 56, respectively.The spectrum of the curative of sample No. 38 is shown in FIG. 69, andthe spectrum of the curative of sample No. 56 is shown in FIG. 70.impurity signals presumably related to the hydrolized products of 2PZLcontained in the curative of sample No. 56 were observed, while nodecomposition of 2PZL was observed from the spectrums of the curative ofsample No. 38. From this results, it is obvious that the storagestability of the curatives according to the present invention is soexcellent.

EXAMPLE 15 Measurements of Hygroscopy of Curatives (Part 4)

2 g powder of the inventive curative of sample No. 27 described in Table1 was placed in a petri dish having a diameter of 3 cm, and thehygroscopy of the curative was determined according to the proceduredescribed in the example 12. Similarly, measurements of hygroscopy werealso made for the curative of sample No. 28 according to the sameprocedure. The results are shown in Table 12. It is found that thesecuratives showed to have no hygroscopic property even under high humidatmosphere.

COMPARISON EXAMPLE 14

2 g powder of a curative of sample No. 52 described in Table 3 wasplaced in a petri dish having a diameter of 3 cm, and the hygroscopy ofthe curative was measured according to the procedure described in theexample 12, and the results are shown in Table 12. The curative showedits hygroscopic property of approximately 3% by weight after 3 dayslaying under an atmosphere of 40° C. and 90% R.H. or approximately 4.5%by weight when it was placed for 2 days under an atmosphere of 50° C.and 90% R.H.

From the comparison between the result in the example 15 and that of thecomparison example 14, it is shown that the curative of sample No. 52conventionally-used showed remarkable hygroscopic property after layingthem under high humid atmosphere, while it is obviously understood thatthe inventive curatives of sample Nos. 27 and 28 showed no hygroscopicproperty under the same condition and they have an excellent property ofstorage stability, respectively.

TABLE 11 Test Change in Weight (wt. %)‡ Period Test Curative CurativeCurative (Days) Condition Sample No. 36 Sample No. 38 Sample No. 56 0 00 0 1 40° C. −0.10 −0.20 7.12 2 R. H. 90% −0.02 −0.15 5.88 3 0.12 −0.064.97 4 50° C. 0.12 −0.09 6.73 5 R. H. 90% 0 −0.10 5.79 ‡Change in Weight(wt %) = {[(Weight of Curative after Testing) − (Weight of Curativebefore Testing)]/(Weight of Curative before Testing) } × 100

TABLE 12 Test Change in Weight (wt. %)‡ Period Test Curative CurativeCurative (Days) Condition Sample No. 27 Sample No. 28 Sample No. 52 0 00 0 1 40° C. −0.19 −0.17 1.53 2 R. H. 90% −0.22 −0.18 2.19 3 −0.17 −0.172.70 4 50° C. −0.21 −0.22 3.90 5 R. H. 90% −0.21 −0.2 4.41 ‡Change inWeight (wt %) = {[(Weight of Curative after Testing) − (Weight ofCurative before Testing)]/(Weight of Curative before Testing) } × 100

EXAMPLE 16 Measurements of Subliming Property of Curatives (Part 1)

The inventive curative of sample No. 10 described in Table 1 was heldfor 30 min. by using a thermal analyzer (TG) at 100° C., and the changein the weight of the curative was checked. Similarly, such change inweight was also checked for a curative of sample No. 11, and the resultsare shown in Table 13. Further, these curatives were held for 30 min. byusing a thermal analyzer (TG) at 150° C., and the change in the weightof these curatives was checked, respectively. The results are shown inTable 14. It is found that no change in the weight was observed forthese curatives when they were held for 30 min. at 100° C. and for 30min. at 150° C., respectively.

COMPARISON EXAMPLE 15

Weight change after holding at 100° C. and 150° C. was checked for thecuratives of sample Nos. 48 and 49 described in Table 3 according to theprocedure described in the example 16, respectively. The results at 100°C. and 150° C. are shown in Table 13 and Table 14, respectively. In caseof the curative of sample No. 48, weight change of 10% was observed by30 min. holding at 100° C. and weight change of approximately 20% wasobserved by 30 min. holding at 150° C. Whereas, in case of the curativeof sample No. 49, weight change of approximately 9% was observed by 30min. holding at 100° C. and weight change of approximately 20% wasobserved by 30 min. holding at 150° C.

From the comparison between the result in the example 16 and that of thecomparison example 15, it is shown that the curatives of sample Nos. 48and 49 conventionally-used showed subliming property, while it isobviously understood that the inventive curatives of sample Nos. 10 and11 showed to have no subliming property but they have an excellentproperty of storage stability, respectively.

TABLE 13 Change in Weight (wt. %)‡ Curative Curative Curative CurativeTest Period Test Sample Sample Sample Sample (min) Condition No. 10 No.11 No. 48 No. 49 0 0 0 0 0 5 100° C. −0.1 −0.3 −2.8 −4.9 10 Fold −0.2−0.3 −6.0 −6.2 20 −0.2 −0.3 −8.1 −7.6 30 −0.2 −0.4 −10.0 −8.6 ‡Change inWeight (wt. %) = {[(Weight of Curative after Testing) − (Weight ofCurative before Testing)]/(Weight of Curative before Testing) } × 100

TABLE 14 Change in Weight (wt. %)‡ Curative Curative Curative CurativeTest Period Test Sample Sample Sample Sample (min) Condition No. 10 No.11 No. 48 No. 49 0 0 0 0 0 5 150° C. −0.2 −0.3 −9.8 −7.0 10 Fold −0.4−0.3 −19.1 −15.2 20 −0.6 −0.5 −20.7 −20.3 30 −0.6 −0.8 −20.9 −22.0‡Change in Weight (wt %) = {[(Weight of Curative after Testing) −(Weight of Curative before Testing)]/(Weight of Curative before Testing)} × 100

EXAMPLE 17 Measurements of Subliming Property of Curatives (Part 2)

Using the inventive curative of sample No. 24 described in Table 1,weight change of the curative when it was held for 30 min. at 100° C.and for 30 min. at 150° C. were checked according to the proceduredescribed in the example 16. The results at 100° C. and 150° C. areshown in Table 15 and Table 16, respectively. It is found that no changein the weight was observed for the curative when it was held for 30 min.both at 100° C. and 150° C.

COMPARISON EXAMPLE 16

Weight change after holding at 100° C. and 150° C. was checked for thecurative of sample Nos. 50 described in Table 3 according to theprocedure described in the example 16. The results at 100° C. and 150°C. are shown in Table 15 and Table 16, respectively. Weight change ofapproximately 3% was observed for the curative by 30 min. holding at100° C. and weight change of approximately 12% was observed by 30 min.holding at 150° C.

From the comparison between the result in the example 17 and that of thecomparison example 16, it is shown that the curative of sample No. 50conventionally-used showed subliming property, while it is obviouslyunderstood that the inventive curative of sample No. 24 and 11 showed tohave no subliming property but it has an excellent property of storagestability.

TABLE 15 Change in Weight (wt %)‡ Test Period Test Curative Sample No.Curative Sample No. (min.) Condition 24 50 0 0 0 5 100° C. 0 −0.3 10Fold 0 −0.8 20 −0.1 −1.7 30 −0.1 −2.8 ‡Change in Weight (wt. %) ={[(Weight of Curative after Testing) − (Weight of Curative beforeTesting)]/(Weight of Curative before Testing) } × 100

TABLE 16 Change in Weight (wt %)‡ Test Period Test Curative Sample No.Curative Sample No. (min.) Condition 24 50 0 0 0 5 150° C. −0.3 −2.0 10Fold −0.6 −4.6 20 −0.7 −8.2 30 −1.0 −11.8 ‡Change in Weight (wt. %) ={[(Weight of Curative after Testing) − (Weight of Curative beforeTesting)]/(Weight of Curative before Testing) } × 100

EXAMPLE 18 Measurements of Subliming Property of Curatives (Part 3)

Using the inventive curatives of sample Nos. 36 and 38 described inTable 1, weight change of these curatives when they were held for 30min. at 100° C. and for 30 min. at 150° C. were checked according to theprocedure described in the example 16. The results at 100° C. and 150°C. are shown in Table 17 and Table 18, respectively. It is found that nochange in the weight was observed for the curatives when they were heldfor 30 min. both at 100° C. and 150° C., respectively.

COMPARISON EXAMPLE 17

Weight change after holding at 100° C. and 150° C. was checked for thecurative of sample Nos. 56 described in Table 3 according to theprocedure described in the example 16. The results at 100° C. and 150°C. are shown in Table 17 and Table 18, respectively. Weight change ofapproximately 4% was observed for the curative by 30 min. holding at100° C. and weight change of approximately 10% was observed by 30 min.holding at 150° C.

From the comparison between the result in the example 18 and that of thecomparison example 17, it is shown that the curative of sample No. 56conventionally-used showed subliming property, while it is obviouslyunderstood that the inventive curatives of sample Nos. 36 and 38 showedto have no subliming property but they have an excellent property ofstorage stability, respectively.

TABLE 17 Test Change in Weight (wt. %)‡ Period Test Curative CurativeCurative (min) Condition Sample No. 36 Sample No. 38 Sample No. 56 0 0 00 5 100° C. 0 0 −1.5 10 Fold −0.1 0 −1.8 20 −0.3 −0.1 −2.4 30 −0.4 −0.1−3.8 ‡Change in Weight (wt. %) = {[(Weight of Curative after Testing) −(Weight of Curative before Testing)]/(Weight of Curative before Testing)} × 100

TABLE 18 Test Change in Weight (wt. %)‡ Period Test Curative CurativeCurative (min) Condition Sample No. 36 Sample No. 38 Sample No. 56 0 0 00 5 150° C. −0.2 −0.2 −4.6 10 Fold −0.3 −0.4 −6.8 20 −0.5 −0.5 −8.5 30−0.6 −0.7 −9.8 ‡Change in Weight (wt. %) = {[(Weight of Curative afterTesting) − (Weight of Curative before Testing)]/(Weight of Curativebefore Testing) } × 100

EXAMPLE 19 Demonstration of Curing Effect of Curatives at LowTemperature (Part 1)

To 100 parts by weight of a base resin (uncured resin), Epicoat 1004(Manufactured by Yuka Shell Co., Ltd.), was compounded 0.95 parts byweight (equivalent to 0.44 parts by weight based on 1B2MZ) of theinventive curative of sample No. 27 described in Table 1, and theresulting mixture was kneaded for 30 min. at 80° C. and then cooled downto room a temperature to prepare a resin composition. Then, the part ofthe composition was collected and was used to determine the curingtemperature of the resin composition from the peak of generated heatduring the curing by using a thermal analyzer (DSC). As a result, it isfound that the peak of heat generated from the resin composition at thereaction was 148° C. The DSC chart of the resin composition is shown inFIG. 71.

COMPARISON EXAMPLE 18

Using 1.08 parts by weight (equivalent to 0.44 parts by weight based on1B2MZ) of a curative of sample No. 52 described in Table 3, a resincomposition was prepared according to the procedure described in theexample 19, and the curing temperature of the said resin composition wasmeasured by using DSC. The peak of heat generated from the resincomposition at a reaction was 168° C. Also, another resin compositionwas prepared according to the procedure described in the example 19 byusing 0.44 parts by weight of 1B2MZ as a curative, and the curingtemperature was measured according to the method as described above. Asa result, the peak of heat generated from the later resin composition ata reaction was found to be 170° C. The DSC chart of the later resincomposition is shown in FIG. 72.

From the comparison between the result in the example 19 and that of thecomparison example 18, it is shown that the peak of heat generated fromthe resin compositions using either a curative of sample No. 52 beingused in the past or 1B2MZ were more or less 170° C. Therefore, it isnoted that high temperature as high as 170° C. is required to thoroughlycure these resin compositions. On the other hand, the resin compositionwhich contains the inventive curative of sample No. 27 has a lower peakof heat at reaction as low as 148° C., and therefore, it is possible tothoroughly cure the resin composition at a temperature which is 20° C.lower than the case of this comparison example. Considering this result,it is obvious that the inventive curative has an excellent curability atlow temperatures.

EXAMPLE 20 Demonstration of Curing Effect of Curatives at LowTemperature (Part 2)

To 100 parts by weight of a base resin (uncured resin), Epicoat 1004(Manufactured by Yuka Shell Co., Ltd.), was compounded 0.95 parts byweight (equivalent to 0.44 parts by weight based on 1B2MZ) of theinventive curative of sample No. 27 described in Table 1, and theresulting mixture was kneaded for 30 min. at a room temperature toprepare a resin composition. Then, the part of the composition was heldat 120° C. by using a thermal analyzer (DSC) to determine the peak areaof heat generated during the curing of the resin composition. As aresult, it is found that the resin composition generated heat of 150jule/g during the curing at 120° C.

COMPARISON EXAMPLE 19

Using 1.08 parts by weight (equivalent to 0.44 parts by weight based on1B2MZ) of a curative of sample No. 52 described in Table 3, a resincomposition was prepared according to the procedure described in theexample 20. Then, the part of the resin composition was collected andheld at 120° C. by using a thermal analyzer (DSC) to determine the peakarea of heat generated during the curing of the said composition. As aresult, the resin composition generated heat of 27 jule/g during thecuring at 120° C. Similarly, another resin composition was prepared byusing 0.44 parts by weight of 1B2MZ as a curative according to theprocedure described in the example 20, and the peak area of heatgenerated during curing according to the method as described above. As aresult, it is found that the later resin composition generated heat of30 jule/g during the curing at 120° C.

From the comparison between the result in the example 20 and that of thecomparison example 19, it is shown that the generated amount of heatfrom the resin compositions using either a curative of sample No. 52being used in the past or 1B2MZ during curing at 120° C. were too smallto initiate the curing. However, the resin composition which containsthe inventive curative of sample No. 27 generated 5 times larger heatthan the heat generated in this comparison example even at a lowtemperature of 120° C. Considering this result, it is obvious that theinventive curative has an excellent curability at low temperatures.

EXAMPLE 21 Demonstration of Curing Accelerating Effect of TetrakisphenolCompounds on Paint Compositions and Resin Compositions

To 100 parts by weight of a base resin (uncured resin), UVR-6410 (Tradename, Manufactured by Union Carbide Co., Ltd.), were added 4.0 parts byweight of 1B2MZ and 5.0 parts by weight of TEP. After kneading themixture for 10 min. at 25° C. and then allowing it to stand for 20 min.at 25° C., the initial viscosity of the resulting resin composition wasthen measured. Then, the resin composition was laid at 25° C., and theperiodical change in the viscosity was measured. Measurements ofviscosity were done according to JIS K-6833-1994, for which B8R-typerotary viscosity meter (Manufactured by Tokyo Keiki Co., Ltd.) was used.The results of the measurements are shown in Table 19. If the pot lifeof the resin composition is defined as time required to make theviscosity of the resin to the double value of the initial viscosityvalue, the pot life of the resin composition was approximately one hour.

Further, in the test described above, measurements of the pot life ofthe resin composition, wherein 4.0 parts by weight of 2E4MZ was usedinstead of 1B2MZ, was performed according to the procedure as describedabove. As results shown in Table 19, the pot life of the resincomposition was 2 hours. Again, in the test described above,measurements of the pot life of a resin composition, wherein 1.0 part byweight of 1B2MZ was used instead of 4.0 parts by weight of 1B2MZ, wasperformed according to the same procedure as described above. As can beunderstood from the result shown in Table 19, the pot life of the resincomposition was 2 hours.

COMPARISON EXAMPLE 20

The pot life of each resin compositions were respectively measuredaccording to the same procedure described in the example 21, except thestep to add TEP. The results are shown in Table 19. The pot life of aresin composition to which 4.0 parts by weight of 1B2MZ was compoundedwas 10 hours. Whereas, the pot life of a resin composition to which 4.0parts by weight of 2E4MZ was compounded was 8 hours. Further, the potlife of a resin composition to which 1.0 part by weight of 1B2MZ wascompounded was 10 hours.

From the comparison between the result in the example 21 and that of thecomparison example 20, it is shown that the pot life of the resincomposition to which TEP was compounded was ¼ to {fraction (1/10)} timeof the one of the resin composition without TEP, and it is obvious thatcured-products can be obtained in a short time when the resincomposition compounded with TEP is used.

Furthermore, when any of phenol, bisphenol A, bisphenol S and1,1-bis(4-hydroxyphenyl)cyclohexane was added instead of TEP in theexample 21 to the resin composition, reduction of the pot life, namelythe effect to accelerate a curing reaction of a resin composition, whichwas noted in case of a resin composition compounded with TEP, was notobserved at all.

TABLE 19 Viscosity of Resin (cp/25° C.) Resin Compounded ResinCompounded Resin Compounded Resin Resin Resin Resin with 4.0% by with4.0% by with 1.0% by Compounded Compounded Compounded Compounded Weight1B2MZ + Weight 2E4MZ + Weight 1B2MZ + with 4.0% by with 4.0% by with1.0% by with 1.0% by Time (h) 5.0% by Weight TEP 5.0% by Weight TEP 5.0%by Weight TEP Weight 1B2MZ Weight 1B2MZ Weight 1B2MZ Weight 1B2MZ 012500 15200 13000 10200 13400 10200 9000 1 23500 20500 19500 10200 1340010200 9000 2 65700 29800 29700 10700 14000 10700 9300 3 377000 4010056800 9900 4 57200 182000 12400 16800 12400 10800 5 88600 12500 6 1480020600 14800 14200 8 2000000 ↑ 2000000 ↑ 2000000 ↑ 16700 25000 1670018400 10 20400 31500 20400 18 120000 120000 24 179000

INDUSTRIAL USE

The curatives for epoxy resins and the curing accelerators for epoxyresins according to the present invention are formed into a clathratecomprising a curative normally used for an epoxy resins and a curingaccelerator for epoxy resins, which are included with a tetrakisphenolhost compound, and are capable of improving the subliming property andthe decomposing property of the curative for epoxy resins and the curingaccelerator for epoxy resins and of steadily remaining in an epoxy resinunder a normal temperature, and they can prolong the pot life of epoxyresins when they are admixed into an epoxy resin. In particular,stability of curatives and curing accelerators to heat, which is anextremely important factor for the control of a curing reaction, isremarkably improved, allowing to cure an epoxy resin even at a lowtemperature. By using the curatives and the curing accelerators, it ispossible to improve working efficiency, and they have better mechanicalstrength and better guest release capability than the microcapsulatedones. Further, the curatives and the curing accelerators according tothe present invention have such advantages that they can faster thecuring speed of a curative for curing epoxy resins, shorten time forcompleting curing of an epoxy resin composition and lower the amount ofa curative being required in the past, and they are useful for variousapplications for curing epoxy resins, for example, epoxy resin-typeadhesives, a sealant for semiconductors, laminates for printed boards,varnish, powder paints, casting materials and inks. In particular, thepresent invention provides excellently suitable epoxy resinscompositions useful as epoxy-type paints, etc.

The curatives and the curing accelerators according to the presentinvention are also applicable for two-pack type thermocurable resincompositions, such as urethane resins and silicon resins, which caninitiate a curing reaction just by mixing a main component and asubcomponent, even they are not an epoxy resin.

What is claimed is:
 1. An epoxy resin composition, comprising an epoxyresin prior to curing, and a clathrate comprising a tetrakisphenolcompound represented by a general formula (I) and a compound reactingwith an epoxy group of the epoxy resin to cure the resin,

wherein X represents (CH₂)n, wherein n is 0, 1, 2 or 3, and R¹ to R⁸each represents hydrogen, a lower alkyl, a phenyl optionally substitutedwith halogen or C₁-C₆ alkyl a halogen or a C₁-C₆ alkoxy.